| Subject | Re: [patch 05/15] sched: add a timer to handle CFS bandwidth refresh | From | Peter Zijlstra <> | Date | Mon, 16 May 2011 12:18:08 +0200 |
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On Tue, 2011-05-03 at 02:28 -0700, Paul Turner wrote: > @@ -1003,6 +1003,8 @@ enqueue_entity(struct cfs_rq *cfs_rq, st > > if (cfs_rq->nr_running == 1) > list_add_leaf_cfs_rq(cfs_rq); > + > + start_cfs_bandwidth(cfs_rq); > } > > static void __clear_buddies_last(struct sched_entity *se) > @@ -1220,6 +1222,8 @@ static void put_prev_entity(struct cfs_r > update_stats_wait_start(cfs_rq, prev); > /* Put 'current' back into the tree. */ > __enqueue_entity(cfs_rq, prev); > + > + start_cfs_bandwidth(cfs_rq); > } > cfs_rq->curr = NULL; > }
OK, so while the first made sense the second had me go wtf?!, now I _think_ you do that because do_sched_cfs_period_timer() can return idle and stop the timer when no bandwidth consumption is seen for a while, and thus we need to re-start the timer when we put the entity to sleep, since that could have been a throttle.
If that's so then neither really do make sense and a big fat comment is missing.
So why not start on the same (but inverse) condition that makes it stop?
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